An Abbott’s Booby Papasula abbottion Rota, Mariana Islands: first … abbotti... · 2017. 3. 15. · An Abbott’s Booby Papasula abbottion Rota, Mariana Islands: first historical

An Abbott’s Booby Papasula abbotti on Rota, MarianaIslands: first historical record for the Pacific Ocean

by H. Douglas Pratt, Michael L. P. Retter, Douglas Chapman, W. Michael Ord & Paul Pisano

Received 21 May 2008

SUMMARY.—We describe the first documented record of Abbott’s Booby Papasulaabbotti in the North Pacific, a female observed and photographed at Rota, thesouthernmost island in the Commonwealth of the Northern Mariana Islands(USA), in northern Micronesia, on 17 April 2007. Furthermore, on the same island,we also observed and photographed a subadult Red-footed Booby Sula sula with ablack-tipped pink bill very similar to that of Abbott’s. The available evidencesuggests that pink is a normal but poorly documented bill colour variation forsome older immature Red-footed Boobies and not a diagnostic feature of Abbott’sor an indication of hybridisation between the two species.

Abbott’s Booby Papasula abbotti is a rare and endangered member of the Sulidae with arelict distribution (BirdLife International 2000, Commonwealth of Australia 2001).Originally placed in the genus Sula, it is quite distinct from the more typical boobies (Olson& Warheit 1988). The species is currently known to nest only on the Australian territory ofChristmas Island in the Indian Ocean (Yorkston & Green 1997; Fig. 1a), and is observed

Figure 1. a) Map of the Indo- Pacific showing important localities mentioned in the text; b) The MarianaIslands, North Pacific Ocean; c) Island of Rota, showing sighting location of Abbott’s Booby, geographicfeatures mentioned in the text, main towns, and highest elevation.

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infrequently at sea in the nearby ocean north to Java (Becking 1976, Dunlop et al. 2001).However, the type specimen was collected 6,300 km west of Christmas on AssumptionIsland, in the Aldabra Group north of Madagascar (Ridgway 1893, Skerrett et al. 2001),where the species is apparently extirpated (Nelson 1974, Prys-Jones et al. 1981). A few sight-ings from the Chagos Archipelago, between Assumption and Christmas islands (Bourne1971, Hirons et al. 1976; Fig. 1a), including a 1996 observation of an immature visiting a large mixed- species seabird roost with Red- footed Boobies Sula sula (Symens 1999), suggest thepossibility of a small remnant or incipient colony. Pre- cultural remains in the Mascarenes(Nelson 1974, Bourne 1976), as well as 6,000 km to the east on Tikopia (Steadman et al. 1990)and Efate (Steadman 2006) in eastern Melanesia, indicate that P. abbotti formerly had a muchwider distribution, extending into the western South Pacific. A different subspecies (orspecies) P. a. costelloi is known from bones found in the Marquesas in eastern Polynesia(Steadman et al. 1988, Steadman 2006). Today, Abbott’s Booby is almost never seen far fromChristmas Island, although the 1990s Chagos sightings may have involved birds from there,and individuals disappear from the colony for long periods supposedly on distant foragingjourneys (Commonwealth of Australia 2001). Balen (1996) summarised recent sightings inthe Banda Sea in eastern Indonesia, and there are three recent ‘continental’ Australiarecords (Hassel & Boyle 1999, Palliser 2005, 2007). We report here the observation of a sin-gle female Abbott’s Booby at Rota, the southernmost island in the Commonwealth of theNorthern Mariana Islands (USA), in northern Micronesia (Fig. 1b). It is the first historicalrecord from the Pacific, and the first ever for the North Pacific.

On 17 April 2007, as participants in a research expedition under the auspices of theNorth Carolina State Museum of Natural Sciences, we were observing birds from theclifftop platform above the seabird colony in Chenchon Bird Sanctuary on the south- eastcoast of Rota (Fig. 1c), encompassing Puntan Saguagahga (= Funiya Point). It is the onlylarge seabird nesting colony in the main inhabited islands of the commonwealth, and thesanctuary provides both legal and physical (low- canopy trees between sheer cliffs and thesea) protection. Weather was characteristically hot with a clear blue sky as hundreds of Red- footed Boobies S. sula circled overhead or perched in their nest trees. Also present werelesser numbers of Brown Booby S. leucogaster, Brown Noddy Anous stolidus, White- tailedPhaethon lepturus and Red- tailed Tropicbirds P. rubricauda, Great Frigatebird Fregata minorand Common Fairy (White) Tern Gygis alba. At c.14.30 hrs, from the north- eastern visibleterminus of the cliff, an unusual- looking booby flew toward us. It had a large head and nar-row wings compared to the other boobies present, and was ‘ungainly and prehistoric- looking’ (MLPR field notes). It had a black tail and a black facial markingaround the eye at the base of the upper mandible, which contrasted with the white head,neck and underparts. Based on the black tail and partial mask, some of us initially suspect-


Captions to figures on opposite page (a colour PDF can be downloaded at www.boc-online.org/bulletin-downloads.htm).

Figure 2 (top left). Abbott’s Booby Papasula abbotti, Rota, Northern Mariana Islands, 17 April 2007 (M. L. P.Retter)

Figure 3 (top right). Field sketch by P. Pisano drawn shortly after sighting of Abbott’s Booby Papasula abbottion Rota, Northern Mariana Islands, 17 April 2007. Notes read as follows: A) bird from above; B) pinkish billwith black tip; C) mostly white body possibly with darker feathers interspersed; D) white head with thinnerneck; E) solid, satin black upper surface of the wings— no white feathering and no clear difference betweencoverts and remiges; F) white rump? G) black tail.

Figure 4 (bottom). (a–c) Three views of probably the same subadult Red- footed Booby Sula sula showing black- tipped pink bill similar to that of Abbott’s Booby Papasula abbotti, Rota, Northern Mariana Islands, 17April 2007. (d) Subadult Red- footed Booby showing Abbott’s- like black- tipped pink bill, Ulupau Head,Oahu, Hawaii, August 1974. (Photograph a by D. Gemmill, photographs b–d by H. D. Pratt.)


4a 4b

4c 4d


2 3


H. Douglas Pratt et al. 90 Bull. B.O.C. 2009 129(2)

ed the bird might be a juvenile Masked Booby S. dactylatra, a rare bird at this locality(Reichel 1991). As the bird circled and flew past us again, lower and c.60–100 m away, itafforded a good view of both wing surfaces. MLPR took a single photograph (Fig. 2) beforethe bird disappeared.

We identified it as an adult female Abbott’s Booby based on the following: the bill was rose- pink with a dark tip (juveniles and adult males have a black- tipped grey bill; Pizzey &Knight 1997); the black marking on the face was confined to the lores at the base of theupper mandible and did not extend below the gape; the head, neck, nape and most of theunderparts and underwings were white, the outermost primaries having black tips; theupperwings were black or very dark brown, with sharp, clean margins where they met thewhite central back; the rump was white with black mottling near the tail; and the posteriorflanks just behind the wings exhibited an odd- shaped black patch, just visible in Fig. 2. Wedid not note feet and leg colours. PP made a field sketch with notes of the dorsal surface(Fig. 3). These include nearly all of the field marks given by Pizzey & Knight (1997).

We returned to the colony next day in the late afternoon, and PP spotted what hethought might be the same bird, circling at great distance with large numbers of Red- footed Boobies offshore, apparently preparing to return to the colony to roost. The birdnever came sufficiently close for a positive identification. We subsequently learned that thecolony extends quite far to the east, with only about one- third visible from the lookout.Perhaps the Abbott’s Booby was roosting in the inaccessible portion. Abbott’s is the onlybooby other than Red- footed (Schreiber et al. 1996) that nests and roosts in trees (Nelson &Powell 1986, Yorkston & Green 1997), which may explain why the bird was attracted to thissite. Interestingly, another seabird endemic to Christmas Island, the golden subspecies of White- tailed Tropicbird P.l. fulva, is also a rare visitor to the Marianas, with records forSaipan (Pratt & Bruner 1981), Guam (Pratt et al. in prep.) and perhaps Rota (Pratt et al. 1987;based on hearsay, with source lost, HDP).

Another intriguing observation on the second day was of a subadult Red- footed Boobywith a black- tipped pink bill very similar to that of Abbott’s (Fig. 4a–c). We were unawarethat some Red- footed can have this bill colour, and have found no description or illustra-tion of it in any field guide. Schreiber et al. (1996) stated that the dark bill of the juvenilebecomes pale grey with a black tip in immatures, before reaching the pink- based blue billof adults. At no stage during such a transition would one expect the bill to be largely pink.We considered the possibility that the pink- billed bird might be a Red- footed × Abbott’shybrid, but later, among old photographs, found an example of a similar pink- billed birdfrom Hawaii (Fig. 4d), indicating that pink is a normal, albeit atypical and poorly docu-mented, bill colour variation for some older immature Red- footed Boobies and not adiagnostic feature of Abbott’s or an indication of hybridisation. Recently, observers at theGreat Barrier Reef misidentified a pink- billed Red- footed as an Abbott’s (D. J. James in litt.2008). We offer our photographs to bolster the literature on maturational stages of Red- footed Booby and to help future observers avoid such errors.

We encourage future visitors to Rota to look for this Abbott’s Booby to determinewhether it was simply a long- distance vagrant or is a solitary resident. If the latter, the birdmight indicate a (re)colonisation attempt or even a relict colony.

AcknowledgementsColleagues present in addition to the authors were Romney Bathurst, William Mueller and Daphne Gemmill.We thank the last- named for the use of her photographs. Our expedition was funded by contributions fromthe participants to the Friends of the North Carolina State Museum of Natural Sciences, which institutionalso supported HDP’s research, and provided computers and software used in preparation of the manuscript


and figures. Referees R. Pitman and D. J. James offered suggestions and additional information that bothshortened and strengthened this report.

References:van Balen, S. 1996. Note on observations of Abbott’s Booby in the Banda Sea. Kukila 8: 145.Becking, J.-H. 1976. Feeding range of Abbott’s Booby Sula abbotti at the coast of Java. Ibis 118: 589–590.BirdLife International. 2000. Threatened birds of the world. Lynx Edicions, Barcelona & BirdLife International,

Cambridge, UK.Bourne, W. R. P. 1971. The birds of the Chagos Group, Indian Ocean. Atoll Res. Bull. 149: 175–207.Bourne, W. R. P. 1976. On subfossil bones of Abbott’s Booby Sula abbotti from the Mascarene Islands, with a

note on the proportions and distribution of the Sulidae. Ibis 118: 119–123.Commonwealth of Australia. 2001. Background information for the Abbott’s Booby, Papasula abbotti recov-

ery plan. Dept. of the Environment and Heritage, Canberra.Dunlop, J. N., Surman, C. A. & Wooller, R. D. 2001. The marine distribution of seabirds from Christmas

Island, Indian Ocean. Emu 101: 19–24.Hassel, C. J. & Boyle, A. N. 2000. Abbott’s Booby: first record for mainland Australia. Australian Bird Watcher

18: 255–258.Hirons, M. J., Bellamy, D. J. & Sheppard, C. 1976. Birds on the Chagos Bank. Nature 260: 387.Nelson, J. B. 1974. The distribution of Abbott’s Booby Sula abbotti. Ibis 116: 368–369.Nelson, J. B. 1978. The Sulidae. Oxford Univ. Press.Nelson, J. B. & Powell, D. 1986. The breeding ecology of Abbott’s Booby Sula abbotti. Emu 86: 33–46.Olson, S. L. & Warheit, K. I. 1988. A new genus for Sula abbotti. Bull. Brit. Orn. Cl. 108: 9–12.Palliser, T. 2005. Submission No. 432: Abbott’s booby Papasula abbotti. Birds Australia Records Committee

(BARC). http://users.bigpond.net.au/palliser/barc/SUMM432.htm (accessed 27 April 2008).Palliser, T. 2007. Submission No. 541: Abbott’s booby Papasula abbotti. Birds Australia Records Committee

(BARC). http://users.bigpond.net.au/palliser/barc/summ541.htm (accessed 17 September 2008).Pizzey, G. & Knight, F. 1997. Field guide to the birds of Australia. Angus & Robertson, Sydney.Pratt, H. D. & Bruner, P. L. 1981. Noteworthy records of nonbreeding birds in Micronesia. Micronesica 17:

195–198.Pratt, H. D., Bruner, P. L. & Berrett, D. G. 1987. A field guide to the birds of Hawaii and the tropical Pacific.

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Ketebengang, H., Olsen, A., Pisano, P. & Yalap, Y. P. In prep. Noteworthy bird observations inMicronesia, with indications of trends among seasonal visitors.

Prys-Jones, R. P., Prys-Jones, M. S. & Lawley, J. C. 1981. The birds of Assumption Island, Indian Ocean: pastand future. Atoll Res. Bull. 248.

Reichel, J. D. 1991. Status and conservation of seabirds in the Mariana Islands. Pp. 248–262 in Croxall, J. P.(ed.) Seabird status and conservation: a supplement. International Council for Bird Preservation,Cambridge, UK.

Ridgway, R. 1893. Descriptions of some new birds collected on the islands of Aldabra and Assumption,northwest of Madagascar, by Dr. W. L. Abbott. Proc. US Natl. Mus. 16: 597–600.

Schreiber, E. A., Schreiber, R. W. & Schenk, G. A. 1996. Red- footed Booby (Sula sula). In Poole, A. & Gill, F.(eds.) The birds of North America, 241. Acad. Nat. Sci., Philadelphia, PA & American Ornithologists’Union, Washington DC.

Skerrett, A., Bullock, I. & Disley, T. 2001. Birds of the Seychelles. Princeton Univ. Press.Steadman, D. W. 2006. Extinction and biogeography of tropical Pacific birds. Univ. of Chicago Press.Steadman, D. W., Schubel, S. E. & Pahlavan, D. 1988. A new subspecies and new records of Papasula abbotti

(Aves: Sulidae) from archaeological sites in the tropical Pacific. Proc. Biol. Soc. Wash. 101: 487–495.Symens, P. 1999. Breeding seabirds of the Chagos Archipelago. Pp. 257–272 in Sheppard, C. R. C. & Seaward,

M. R. D. (eds.) Ecology of the Chagos Archipelago. Linnean Soc. Occas. Publ. 2. Westbury Publishing, Otley.Yorkston, H. D. & Green, P. T. 1997. The breeding distribution and status of Abbott’s Booby (Sulidae:

Papasula abbotti) on Christmas Island, Indian Ocean. Biol. Conserv. 79: 293–301.

Addresses: H. Douglas Pratt, North Carolina State Museum of Natural Sciences, 11 West Jones Street, Raleigh,NC 27601, USA, e- mail: [email protected]. Michael L. P. Retter, 3346 Peppermill Drive, WestLafayette, IN 47906, USA. Douglas Chapman, 3108 S Holly Avenue, Sioux Falls, SD 57105, USA. W.Michael Ord, 1178 Hunakai Street, Honolulu, HI 96816, USA. Paul Pisano, 626 18th Street South,Arlington, VA 22202, USA.

© British Ornithologists’ Club 2009

H. Douglas Pratt et al. 91 Bull. B.O.C. 2009 129(2)


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An Abbott’s Booby Papasula abbottion Rota, Mariana Islands: first … abbotti... · 2017. 3. 15. · An Abbott’s Booby Papasula abbottion Rota, Mariana Islands: first historical